Make GITEA_API_TOKEN required for automatic deployments

Automatic deployments are essential for the template, so GITEA_API_TOKEN is now required.

Changes:
- .env.example: Marked both API keys as REQUIRED
- deploy-to-apps.example.sh: Script now exits with error if GITEA_API_TOKEN not set
- Added clear instructions on how to get Gitea API token

Without webhooks, users would need to manually trigger deployments after every push,
which defeats the purpose of automated infrastructure.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

.env.example

@@ -65,10 +65,10 @@ DB_PASSWORD=
 # ===================================
 # API Tokens (for deployment script)
 # ===================================
-# Get your SAAC_API_KEY from: https://apps.startanaicompany.com/api/v1/register
+# REQUIRED: Get your SAAC_API_KEY from: https://apps.startanaicompany.com/api/v1/register
 # Set as environment variable: export SAAC_API_KEY="your_key_here"
 #
-# GITEA_API_TOKEN is optional - only needed for automatic webhook setup
+# REQUIRED: GITEA_API_TOKEN needed for automatic deployments (webhook setup)
 # Get from: https://git.startanaicompany.com → Settings → Applications → Generate New Token
 # Set as environment variable: export GITEA_API_TOKEN="your_token_here"